The present invention relates to a rolling bearing unit for wheel support suitable for rotatably supporting vehicle wheels on a suspension.
A rolling bearing unit of this sort comprises an outer ring, an inner shaft disposed concentrically with and radially inward of the outer ring and having an inner ring fitting part on the outer peripheral surface on one axial direction side. The unit also includes an inner ring fitted on the inner ring fitting part.
The above unit is configured so that, in a state where the outer end face on the one axial end side of the inner ring is pressed in the axial direction, the one axial direction side inner shaft end is crimped on the outer end face of the inner ring end. Such a rolling bearing unit is disclosed in Laid-Open Japanese Patent Applications 2001-248650 and H10-272903.
However, when the inner shaft end on the one axial direction side is crimped on the outer face of the inner ring end, force is generated on the inner ring end part. The force presses against the inner ring and spreads the inner ring radially outward, with the danger that the fitting position of the inner ring inside the rolling bearing unit may be affected. Further, when the inner ring has an end part outer peripheral surface with a step formed thereupon, if the inner shaft end is crimped on the outer peripheral surface of the inner ring while the step portion is being pressed in the axial direction, a large force is exerted radially outward on the inner ring. The force causes inclination of the fitting position of the inner ring.